However, when All Things D's Ina Fried asked whether Microsoft would allow Facebook Home -- for now an Android-only app that sits between the user and the smartphone's usual home and "lock" screens -- on Windows Phone, Myerson dodged the question.

While he complimented some of Facebook Home's features, he did not answer Fried's question, instead saying "We'll want to work with them [but] our goal is to provide a platform such as our partners can achieve their differentiation."

Microsoft has taken swipes at Facebook Home before. Two weeks ago, after Facebook unveiled the app-slash-interface for Android, Microsoft's head of communications, Frank Shaw, belittled it as an old idea that was little more than a copy of what Windows Phone launched in 2011.

In an interview today, Patrick Moorhead of Moor Insights & Strategy agreed with Shaw. "Facebook stole, or copied, many of the ideas that make up Windows Phone 8," said Moorhead.